Gas burner



July 18, 1961 J. R. WILLIAMS GAS BURNER 2 Sheets-Sheet 1 Filed Sept. 25,1958 FIG.

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INVENTOR. JOHN ROGER WILLIAMS ATTORNEY.

July 18, 1961 J. R. WILLIAMS GAS BURNER 2 Sheets-Sheet 2 Filed Sept. 25,1958 FIG. 3

FIG. 5

INVENTOR. JOHN ROGER WILLIAMS pmw flw ATTORNEY.

United vStates Patent 2,992,677 GAS BURNER John Roger Williams, Ambler,Pa., assignor to Selas Corporation of America, Dresher, Pa., acorporation of Pennsylvania Filed Sept. 25, 1958, Ser. No. 763,325 2Claims. ('Cl. 158-117) The present invention relates to burners and moreparticularly to combustion chamber type burners having variable andinterchangeable discharge orifices.

The heating of metal for hardening, brazing, or other operations hasbeen carried out for a number of years by combustion chamber burners ofthe type shown, for example, in Hess 2,460,085 issued January 25, 1949.

Burners of the type shown in the Hess patent have a discharge slot forthe hot products of combustion that is of a fixed length. This meansthat different burners having discharge slots of different lengths mustbe used for heating work pieces of different lengths or selectedportions of a piece of work of a given contour.

It is an object of this invention to provide means for varying theeffective length and shape of the discharge slot of a combustion chambertype burner.

It is a further object of the invention to provide means for use with acombustion chamber type burner to vary the number, size and location ofa plurality of discharge ports so that a given burner can be used forheating a plurality of parts requiring heat at different specificpoints.

In carrying out the invention, there is provided a water cooled memberfor variably obstructing the discharge slot of a burner. This member canbe shifted to vary the length of the slot, or it may be replaced byanother member provided with discharge openings of fixed size andlocations along the length of the burner slot.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its ad vantages and specific objects attained with its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described a preferred embodimentof the invention.

In the drawings:

FIG. 1 is a section through the burner,

FIG. 2 is a section taken on line 2-2 of FIG. 1,

FIG. 3 is a section showing the outlet portion of a modified form of theburner,

FIG. 4 is a partial section taken on line 4-4 of FIG. 3, and

FIGS. 5 and 6 show alternate arrangements of outlet slots in the blastadjuster.

Referring to FIG. 1, it will be seen that the burner includes a basecasting 1 that is provided with a threaded inlet 2 for a fuel mixtureleading to a supply chamber 3. A passage 4 extends from chamber 3 toform an inlet to the combustion chamber 5 of the burner. A burner screen6 extends across the inlet passage. This screen can well be formed of aplurality of thin ceramic plates with one side of each plate smooth andone side being provided with a series of parallel grooves 7. When theplates are placed side by side, the grooves 7 will form passages throughwhich the fuel mixture will flow from the supply chamber to thecombustion chamber. The plates forming screen 6 rest against shouldersprovided in casting 1, and are held in position by metal plates 8 thatoverlie shoulders formed on the screen, as best shown in FIG. 1 of thedrawing. The plates 8 are held in position by screws 9, and a gas tightjoint is formed along the edges of the screen by a suitable packing 11of asbestos or similar material.

The walls of combustion chamber 5 of the burner are formed by a ceramiccasing 12 that may be made of one or more pieces and which rests uponplates 8. The ceramic casing is held in position on casting 1 by a metalcasing 13 that is preferably formed with spaced apart walls so that thecasing can be water cooled. Cooling water inlets and outlets can beprovided where convenient. As shown herein, casing '13 is fastened tothe base casting 1 by suitable screws.

A discharge slot 14 extends from the combustion chamber 5 opposite inlet4, to the exterior of the structure, and is of a length equal to thewidth of the combustion chamber as shown in FIG. 2. The slot isrestricted in its cross section with respect to the size of the crosssection of the combustion chamber. Discharge slot 14 extends throughcasings 12 and 13 and between refractory members 15 and 16 that are heldin position on the outer surface of casing 13 by suitable clamps 17. Itis intended that the outer surface of members 15 and 16 have a contourconforming to the contour of the piece of work being heated and thattheir shape will be varied depending upon the shape of the work beingheated.

The sides of that portion of discharge slot 14 extending through casing13 are recessed as shown at 18. The recesses are continued through oneend of casing 13, as shown in FIG. 2 to form a passage through theburner extending lengthwise of the discharge slot intermediate its ends.A blast adjuster 19 is snugly and slideably received in this passage.This blast adjuster is a tubular metal member which has concentricallyextending into it a cooling fluid supply tube 21, and is provided withan outlet 22.

In the operation of burners of this type, a combustible mixture of gasand air is supplied to chamber 3, and passes through passages 7 of thescreen to be ignited and burned in combustion chamber 5. The interior ofthe combustion chamber becomes intensely hot and serves to pilot theflames so that all of the combustion will take place within thischamber. The hot products of combustion are discharged at high velocityand at substantially the temperature of combustion through therestricted discharge opening 14. These hot products of combustionimpinge against work that is held close to the mouth of the burneradjacent to members 15 and 16 so that the hot products of combustionflow through the narrow space between these members and the work, toheat the work rapidly. An operation of this type is described in theabove mentioned Hess Patent 2,460,085.

It has been customary in the past, to make burners with different lengthslots conforming to the length of the work to be heated. This means thateither the work has the same length and contour or a number of burnerswere needed. With the present invention, however, members 15 and 16 caneasily be replaced by other members having a different contour.Furthermore, the blast adjuster 19 which can be moved axially along thepassage formed by recesses 18 to vary the length of the discharge slot,and thereby change the length of the blast of hot products of combustionto conform to the length of the work to be heated. A cooling fluid suchas water is supplied to tube 21 to flow through the blast adjuster andbe discharged through outlet 22. This cooling fluid is sufiicient tokeep the blast adjuster at a low enough temperature so that it will havea satisfactory service life. The blast adjuster does not appear to haveany particular effect on the temperature or velocity of the hot productsof combustion being discharged through slot 14. Thus, a single burnercan have its outlet or discharge slot adjusted to be used with work ofdifferent length and shape.

In FIG. 3 there is shown a modified form of the invention in which theblast from the combustion chamber is discharged through restricted slot25 directly against the r. I 2,992,677 a work to be heated withoutthe'use of members similar to the refractory members 15 and 16. A slotof this type is used primarily for local or spot heating by the hotproducts of combination rather than for area heating as would be thecase with the burner of FIG. 1. A shown herein, the restricted outletslot extending through casing 24 is provided on each side with a recess26 that extends lengthwise of the slot and is continued through the endsof the casing 2'4 to form a passage as shown in FIG. 4 of the drawing.In this form of the invention, the blast adjuster 27 extends all the Waythrough said passage and at all times obstructs the entire dischargepassage. The blast adjuster, however, is provided with a plurality ofdischarge passages 28 as shown in FIGS. 4 and 5. These passages areformed by walls 29 conforming to the shape and size of the passage whichwalls are welded in position in suitable openings formed in the blastadjuster. As shown in FIG. 5, there are four passages through which thehot products of combustion are discharged, which are designated at 28,28a, 28b, and 280. The hot products of combustionflowing through thesepassages are to be directed locally, for example, against portions ofwork that are to be heated, while other portions of work are not beingheated. A cooling fluid is continually circulated through fittings 34 onthe: ends of the blast adjuster from one end to the other and aroundwalls 29 while the burner is in operation.

FIG. 6 shows a blast adjuster having a different shape set of passagesformed therein. By removing the blast adjuster shown in FIG. forexample, and inserting in passage 26 a blast adjuster similar to thatshown in FIG. 6, different portions of the Work would be heated ordifferent work pieces that require heating at the specific locations infront of the passages 31, 31a, 31b, and 310.

From the above description it will be seen that I have provided acombustion chamber type burner which can be used to heat selectedportions of difiierent size work pieces by merely adjusting the lengthor the shape of the discharge opening. This arrangement permits the useof one burner for heating many pieces by merely changing the position ofor changing the entire Blast adjuster so that the blast will be ofdesired length and shape.

While in accordance with the provisions of the Statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus-disclosed Withoutdeparting from the spirit and scope of the invention set forth in theappended claims,'a'nd that in some cases certain features of myinvention may be used to advantage without a corresponding use of otherfeatures.

What is claimed is:

1. In a burner, the combination of structure including refiractorymaterial forming a combustion chamber having an elongated and restricteddischarge slot extending from said chamber to the exterior of saidstructure, a hollow metallic casing surrounding at least a portion ofsaid structure and said slot to form a water jacket, said casing beingprovided with an opening therein the sides of which form a continuationof said discharge slot, said sides of said opening being concave inshape transverse to said discharge slot to form an enlargement therein,means ito supply cooling water to said casing to flow around saidopening, a tubular member slidably received in said enlargement andoperative as it is moved therealong to block ofi more or less of saiddischarge slot, and means to circulate cooling water through saidmember.

2. The combination of claim 1 in which said member is provided with apassageway diametrically thereof and of less area than said slot throughwhich combustion products can flow from said combustion chamber.

References Cited in the 'file of this patent UNITED STATES PATENTS421,576 Jones et a1 Feb. 18, 1880 418,807 Monroe Jan. 7, 1890 2,460,085Hess Jan. 25, 1949 2,717,416 Fletcher Sept. 13, 1955 2,876,831 KnightMar. 10, 1959

